Reflector



March 22, 1 c. 5.. GODLEY REFLECTOR Filed May 8, 1922 5 Sheets-Sheet 2 March 22, 1927.1 I 1,621,586

- c. E. GODLEY I REFLEQTOR 7 Filed May a. 1922 s sheets -sheet s INVEN TOR.

March 22, 1927.

- c. E. GODLEY REFLECTOR Filed May a, 1922 5 Sheets-Sheet 4 INVENTOR.

- ATTO C. E. GODLEY REFLECTOR March 22, 1927. j 1,621,586

Filed May a, 1922 '5 Sheets-Sheet 5 Patented Mar. :22, 1927.

uNiTE o stares rCH-A'RIIESE. GODLEY,OF DET-ROIT, MICHIGAN, ASSIGNOB'T0 EDMUNDS& JONES =GOR- PORATIQN, =0F.DETROIT, MICHIGAN, A CORPORATION OF NEW YORK.

REFLECTOR.

"This invention relates to the construction of the reflectors of projecting lamps, especially the headlamps of motor vehicles, and its object is to so divide the reflector into sections that the rays of light will be projected upon a clearly defined limited area, and in part concentrated upon airestric't edportion of such area.

Lamp builders have long sought to provide headlights for vehicles which would give "an even illumination of the roadway from immediately in front of the vehicle to'a point in advance thereof suflicient-ly distant to 'permit't'he driver to see and avoid all obstructions, and furthermore, to attain this ojbject with "the least expenditure of electric current. Lamps equipped with the well known parabolic reflectors cannot produce this 'efiect as the illumination of the roadwayat a given distance from the vehicle is'either' -very restricted or is much fainter than theroadway nearerthevehicle. When such lamps are so positioned that the concentrated light properly illuminates the roadway'sufiicient-ly far in-advance to permit "the driver 'to avoid obstructions, the roadway "nearer the vehicle is left dark. Or if the light bulb is so positioned that the projected rays illuminate :the roadway near the vehicle,'too much light is projected upward and sidewisevvhere it is liabretoblind drivers of other vehicles and pedestrians.

My present invention aims to overcome these objections while still employing a simple reflector of a substantially parabolic type,by deforming the reflector so that difterent portions thereof will project beams W hose crossssections are similar in shape butdiiferentin size, so that-the larger beam will afi'ord-a general roa'd-=illumination of considerable spread 'while the more concentrated beam will afl'ord a driving :beam which will light a narrower stretch of road for a'consi'derable distanceahead ofthe vehicle.- iFurthermore, my invention consists in deforming a substantially parabolic reflec'tor -E-.'0 that it will project beams of greater width than height. It also consists in providing a reflector of this character which can be 'manut-actured at approximately thesame cost as an ordinary :paraboloidal reflector and in which \the :special deformations Will not interfere with the usual machine polishing of *the reflecting surface. Moreover, it consists in providing a reflector construction which willb e equally suitable for considerable "variations both "in the spread-of the beams and in their relative intensity, and also adapted to be used tor substantially all purposes here it is desirable to projectbeams ofrel'ative ly ditferent transverse diameters.

r In accomplishing these purposes, I employ a reflector of :a generally paraboloidal form and subdivide this reflector into a plurality of panels which extend transversely of the directions in which the beam {lS'itO "be expanded, each of these panels having its longitudinal medial portion disposed forward ly of the general paraboloida'l form of the reflector farther than -its :laterale-dges. 1 vary the 'depth'or the convexity of *theerosssection or the width of the panels according to the desired spread ofth'e projected beam, r

and varyf-the relation of the "central lines of the panels to the vertical plane passing through the axis of the reflector according to the directions in which the beam is to be expanded. The :cross section of any pa-nel 011'3, line'radial to the inner edge of said panel is the same as a horizontal crots section of the same width of the'deterniining reflector, the center of "this cross section 0f the determining reflector being in a line passing througlrthe focal-center ot bothare fl ec'tors and through substantially therniiddle of-said rcross section of said panel, but ,re-

izontal :axis were all '-in vertical planes, the

beam of the reflector would he expanded from circular to elliptical 'crossssect-ions 'with the major axis of the ellipses :hori s zontal. If :such generally upright panels all curve tslightly vtoward or away from a vertical :plane, the beam will be changed in CIOSSrSGGtiOIl substantially to'th-at of a hori- :zontal rectangle. I,

l/Vhile such alterations in beam sections can be accomplished by means of panels of varying transverse sections, I prefer to conveX each panel forwardly in the relative transverse sections of a parabola of slightly longer focus than the normal parabolic reflector for the greater distribution, and transverse sections of a parabola of a much longer focus for the more concentrated light.

By using the longer-focus transverse sections, the panels can all be of the same width or any predetermined width, the spread of light being determined by the focal length of the parabola used in. determining the transverse sections of the panels.

By using transverse parabolic setions in the panels I find that the light rays reflected from each panel diverge equally from the of the reflector, the rays from each panel covering substantially the anticipated field oflight of the different sections.

I have also found that if the convexity of each panel is just the reverse of the normal parabolic section for the same portion of the reflector, using narrower-panels for greater concentration and wider panels for the more diffused light, that the width of panelsare determined by the width of spread desired in the projected fields.

In the accompanying drawings Fig. 1 is a horizontal section of a reflector embodying the present invention on the line 1+1 of Fig. 2. Figs. 1, 2 1 and 2 are diagrams showing the process for determining the proper cross sections of the paraboloidal panels. Fig. 2 is a front elevation of the reflector. Fig. 3 is a diagram illustrating the effect of the light rays projected by the reflector shown in Figs. 1 and 2. Figs. 4, 5 and 6 are views corresponding to Figs. 1, 2 and 3 respectively of a modified form of reflector. Fig. 7 is a view of another modifled form of reflector. Fig. 8 is a section on the line 88 of Fig. 7. Fig. 9 is a diagram illustrating the effect of the light rays projected by the reflector shown in Fig. 8. Figs. 10'and 11 are respectively elevation and vertical section of another modified form of reflector.

Similar reference characters refer to like parts throughout the several views.

In Figs. 1, 2 and 8, Fig. 2 is a front elevation of a reflector embodying this invention, but Figs. 1 and 3 are to be taken togetherythe observer being supposed to standv at the bottom line of the drawing and look at the diagram" Fig. 3 which, being a vertical plane'receives the rays of light from the reflector 1.-

The reflector 1 is generally parabolic in form. If a light bulb could be made with a filament with substantially no dimensions and th filament mounted at the focus of the reflector, then this reflector, if a perfect parabola, would project a beam of light of the diameter of the reflector. The filaments of light bulbs are, however, of considerable size so that the lig. t projected is in the form ofa cone whose surface is somewhat indefinite.

After the parabola has been formed and polished, it is placed between proper dies and its surface is deformed so as to be divided into panels 3 and 4:, those next the central aperture 2 of therefleotor in Figs. 1

of added diffused light toward the corners of the main projected field.

The desired width of the panels being fixed, the exact cross sections of the panels may be determined after the manner shown in Figs. 1 to 2 inclusive. For any given portion of the panel E shown in Fig. 2*, I first determine the center Gr of the cross-section of the corresponding part of the original or true paraboloidal surface 1, as shown in Fig. l I thendraw a line from this point G to the focus F of the true parabolic surface portion and also plot the corresponding portion of a determining parabola P. The focal length of the reflector 1 is indicated by the line B and that of the parabola P by the line C. The point H at which the focal line F G intersects the determining parabola P indicates the central point of a small section of the parabola P which has the proper curvature for the desired panel cross-section. If this determining parabola is of greater focal length than the parabola 1 (which is part of the true paraboloidal surface from which the reflector is to be formed and which it will still approach rather closely when finished) this curvature is reversed as shown in Figs. l and 1".

- Cross-sections of the panel 3 at other points are similarlydetermined, each being taken radially to the inner edge of the panel as shown by the lines K in F ig. 2. This insures a panel which effects an unusually uniform distribution of light. Owing to the resulting uniform density of the projected beam and of the beam-widening effect due to the edgewise curving of the panels, they cooperate in projecting a beam of approximately rectangular cross-section with its upper and lower borders substantially parallel to the plane ofthe line E in Fig. 2 The lines K, indicate how the rays of light are deflected up. and down so as to proceed along lines substantially at right angles to the border lines-"of the panels at the points of reflection.

W here the panels are at any other angle to the vertical plane of the reflector or reflectors, reversed "and placed so as to coi'ncide with the normal parabolic reflector surface at the edges of each panel and tilted into the planes in which the light is to be spread. The curvature of each panel is therefore greatest at the line 1-1 of Fig. 2, which is the horizontal diameter of the reflector.

Fig. 3 is a diagram A showing the proportionate illumination of a fieldby means of a reflector of this character, the field being divided as shown into eighty squares,

and'the length of the sides of the squares equalling approximately one degree of are on a sphericalsurface Whose ra'diusis one hundred feet, the general focus of the reflector being at the centerof this spherical surface. With the source of illumination at the focal point 9, Fig. 1, some of the i efie'cted light rays are projected by each of the wideand deeply curved panels 3 over a surface extending from "one, vertical line 8 to the other, (and from horizontal line l, and if the panels l were'coated with a nonrefleeting material, it would be observed that theillumination of this area is remarkably uniform. Its side bordersare not as clearly defined as its'upper and lower limits but are still clearly distinguishable. This illumination is 'indijcated'by the lines6 and 12.

The side panels a are narrower than'the middle panels 3 and their transverse curvatures are much less so thatjthe light reflected by these side panels is idiflusedto a much less extent, both horizontally and vertically, as indicated by the lines 9 and 10, for the reason that the narrower panels -approa'cl1 more closely to the true paraboloidal refiector surface. For example, I have found that with the panels proportioned as in Fig. 2, each of these'sidepanelswill projectlight on about the'middle one-fourth of the field illuminated by-rays projected by panels The result is that at any desired'testing distance,'the field or chart shown in Fig. 3 can be illuminated by any combination offbeams of light, that is, more or less concentration or more or less difi'used'light, to the extent of spreading the beam-candle-power of the normal parabolic reflectorover therespective field areas. This is accomplished by varying the proportionate Width of the seclight. It is not my intention to limitanyself to only two beams of light, one within the other, as it may be adva'n'tageous tothr'ow more light onto some other point on the roadway which can easily be accomplished by altering the panels and sections so as to project two or more separate beamsof light. Also it is not my intention to limit myself to the extent that the tops of the separate beams of lightshall=coincide at any particular distance, as it may be desirjable at some time to haveithem coincide at'a less 01' greator distance from thereflector, so the angle of the axes of the two-orm'ore sections 'of the panels mayvary in degree.

It will be observed in Fig. 3, that the upper edge of the area of intense illumination'caused by the panels 4 is between the horizontal line 0 and the line 1 ab'ove, which is above the upper edge of the illumination caused by the. panels 3. This is "produced by'tilting that portion of the reflector which embodies the panels 3 on the focal axisbf the reflector :as a center, as indicated in Figs8 and 9, through an angle sufficient to make these upper 'beamedges differ, which in this instance means 'an 'angle of about one degree. This'ca'uses the point of most intense illumination of the field shown in Fig. 3 to be just below the horizontal'line 1 in stead'of having the intensifiedfield central of the less brightly lighted field.

Figs. 4c, 5 an'd 6"s'how'a reflector 13 having narrow panels 18 near the central opening 2 and wider panels 20 on the outside thereof. Therays reflected by' the narrower panels '18 are concentrated on thespa-ce between the lines '16, the lines 'of reflection being indicated by the lines 16 and 17. *It will be apparent that in"thisjcase, as in that shown in'Figs. 1, 2-and'3,'th'e wider panels diffusethe'light overthe entire area'o'f illumination, of the diagram A of Figfiflbetween the lines 14, the lines ofjreflection'being indicated by the lines 14 and 15. But because of "the shallower curvatures "of the "narrow panels 18,'the illumination ismore closely confined to the space betweenthe lines 16 than in the reflector shown in Fig. 2, whereinthe wider central panels, because of their greater curvature, diffuse the "light laterally beyond the lines -6 to a considerableextent. V

The area diagram A in Fi-gi9jis thesame as in Figs. 3 andfiand the indicat-ions'of degree of illumination-are the same. The scorings of the reflector '13'are the same as shown iniFigs. 4 and- 5 except that'the widths of the wider side panels 20 increase gradually outward. The "angle between the focal axis '23 of the outer two sections comprising the wider paneis'zZO and the focal-axis 24 of the two 1nner sections comprising the narrower panels 18 1s only about one degree although this may be varied as desired. The

an ul! i be said to extend about one hundred feet toward the vehicle. The area of less illumination indicated as being below the line 2 of the diagram extends over practically the one hundred feet of roadway next in front of the vehicle.

I have found that in reshaping a reflector to alter the cross-section of the resulting beam, the panels need not curve toward each other at their ends, as shown in Figs. 1 to 8, but may curve away from each other as do the panels 28 and 29 in the reflector 30 shown in Figs. 10 and 11.

In all of these modifications the ligh will be diflused laterally upwardly and downwardly into the planes of the tilted cross-sections of the panels, having a tendency toward squaring the corners. I

From the above described illustrations-it will be obvious that thevarious features of my invention may be carried out in many different embodiments, and that the construction of reflectors according to my invention may differ widely to produce the desired reshaping of the normal beams from those produced by the general type ofv reflector employed, according to the desired extent of the intensifying or plural beam effect and according to the relative desired position of the different beams. I therefore do not wish to be limited to the particular details of construction and arrangement here disclosed, which obviously might be varied in a great many ways without departing from the spirit of my iany-sided invention. Neither do I wish to be limited to the use of such reflectors for vehicle headlights, asthey might be employed with equal advantage for other purposes, such as show window lights and so-called flood lights.

I claim 1. A paraboloidal reflector composed of I of the reflector.

2. A paraboloidal reflector. composed of a group of panels on each side of the center f the reflector, the panels having parallel sides and the panels of each group being parallel to each other, each panel being transversely convex toward the general focus of the reflector and its transverse curvature at each point being the same as that of the general curve of a parabola at that point but in the opposite direction, the adjacent edges of the two inner panels of the two groups being curv d apart at the cen ter of the reflector, the panels of each group constituting inner and outer sections, and the panels of one section being wider than the other and adapted to produce a grzater diffusion of light.

A ,paraboloidal reflector composed of a group of panels on each side of the center sides and the panels of each group being parallel to each other, each panel being transversely convex toward the general focus of the reflector and its transverse curvature at each point being the same as that of the general curve of a parabola at that point but in the opposite direction, the ad jacent edges of the two'inner panels of the two groups being curved apart at the center of the reflector, the panels of each group constituting inner and outer sections and the general focal axis of the inner sections being at an angle to the general focal axis of the'outer sections. I

4:. A paraboloidal reflector composedo-f a group of panels on eachside of the center of the reflecton'the panelshaving parallel sides and the panels of each group being parallel to each other, eachpanel be'-' ing transversely convex toward the general focus of the reflector and its transverse curvature at each point being the same as that of'the general curve of a parabola at that point but in the opposite direction, the adjacent edges of the two inner panels of the two groups being curved apart at the center of the reflector, the panels .of each group constituting inner and outer. sections and the general focal axis of the inner sections being at an angle tothe general focal. axis of the outer sections, both focal axes being in the same vertical plane.

5. A paraboloidal reflector whose reflecting surface is scored to form panels which are all convex toward the general focus of the reflector, the transverse curvature of each portion of each panel being the same as that of the general curve of a parabola at that point but in the opposite direction.

6. A paraboloidal reflector composed of panels which are all transversely convex to ward the general focus of the reflector the general surface of the panels adjacent the vertical focal plane of the reflector having a focal axis at an angle to the focal axis of the general surface of the remainder of the panels.

7. A substantially parabolic reflect-or com posed of panels of different widths, all exsource of light and having the reflector portion adjacent to one central plane of the re flector formed for projecting a beam of light flattened transversely of the said plane to a substantially rectangular cross-section, the reflector portions lateral of the aforesaid portion being formed for projecting a similarly flattened beam of different cross-section, the two reflector portions being relatively tilted to cause a flat side of one beam to coincide substantially with the flat side of the other beam. I

9. A light concentrating reflector having a horizontal axis and having its reflecting surface scored to form panels which are all convex toward the general focus of the reflector, the transverse curvature of each portion of each panel beingthe same as that of the curve of a determining parabola having the same focal point and focal axis on the determining parabola at the intersection therewith of a line from said focus passing through said portion of the panel, but reversed.

10. A light concentrating reflector having a horizontal axis and having its vertically medial portion tilted so that its axis diverges from the axis of the laterally outward portions of the reflector, the lines of juncture of the said medial section with the reflector portions lateral thereof being bowed towards the vertical medial plane of the re flector, each of the laterally outward portions comprising panels extending from edge to edge of the reflector.

11. A light concentrating reflector having a horizontal axis and having its vertically medial portion tilted so' that its axis diverges from the axis of the laterally outward portions of the reflector, the lines of juncture of the said medial section with the reflector portions lateral thereof being bowed towards the vertical medial plane of the reflector, each of the laterally out ward portions comprising panels extending from edge to edge of the reflector and presenting edges which appear parallel when viewed from the mouth of the reflector.

12. A light concentrating reflectorhaving a horizontal axis and having its vertically medial portion tilted so that its axis di- 5' verges from the axis of the laterally outward portions of the reflector, the lines of juncture of the said medial section with the portions lateral thereof being bowed towards the vertical medial plane of the reflector, each of the said reflector portions comprising panels extending from edge to edge of the reflector, the panels in the medial portion of different width from I those in the laterally outward portions.

13.. A light concentrating reflector having a horizontal axis and having its vertically medial portion tilted so that its axis diverges from the axis of the laterally outward portions of the reflector, the lines of juncture of the said medial section with the reflector portions lateral thereof being bowed towards the vertical medial plane of the reflector, each reflector portion comprising panels extending in the same general direction and each panel being forwardly convexed to an extent increasing from its ends to its middle.

CHARLES. E. GODLEY. 

